4'-Hydroxy aceclofenac suppresses the interleukin-1-induced production of promatrix metalloproteinases and release of sulfated-glycosaminoglycans from rabbit articular chondrocytes

Aceclofenac and methotrexate combination therapy could influence Th1/Th17 axis to modulate rheumatoid-arthritis-induced inflammation

Rheumatoid arthritis (RA) is an inflammatory, autoimmune and connective-tissue arthropathy. The methotrexate (MTX) and aceclofenac (ACL) combination drug regimen is known to regulate the immunological pathways. Also, RA-elicited inflammation is decreased by the combination drug treatment. ACL and MTX combination treatment has been shown to regulate the signaling pathway controlled by NF-κB and FOXO1. The present manuscript reviews the importance of the combination drug regimen to treat and/or manage RA. The combination drug regimen could affect the Th1/Th17 axis to switch the balance toward the immunoregulatory (Th1) phenotype for establishing immune homeostasis. In conclusion, we propose the study of the immunological signaling pathways in experimental humanized RA mice.

The effect of non-steroidal anti-inflammatory drugs on matrix metalloproteinases levels in patients with osteoarthritis

OBJECTIVE

The objective of this study is to determine and comparatively evaluate the effects of three different non-steroidal anti-inflammatory drugs on the levels of metalloproteinases MMP-1, MMP-3 and MMP-8, as well as on their tissue inhibitor TIMP-1, in patients suffering from idiopathic osteoarthritis. The effect of these drugs on the articular cartilage and the probable use of MMPs and TIMP-1 as markers of disease and treatment was also investigated.

METHODS

Thirty-six patients with OA were selected and allocated to three groups on the basis of their disease location. All patients received anti-inflammatory treatment with special selective COX-2 inhibitors, i.e. celecoxib, meloxicam, aceclofenac. Each drug was given to every patient for three months following a randomized order of administration. Serum levels of MMP-1, MMP-3, MMP-8 and TIMP-1, and ratios MMP-1/TIMP-1, MMP-3/TIMP-1, MMP-8/TIMP-1 were measured before and after treatment.

RESULTS

The use of aceclofenac resulted in no significant variation in either MMPs concentration and MMPs/TIMP-1 ratio. This outcome concerns the three groups and the 36 patients that form them. After all patients had received all three NSAIDs, MMPs and TIMP-1, these parameters were compared to their initial and final median values. A significant reduction in MMP-3 was found so in all OA patients as in the group of knee OA patients.

CONCLUSIONS

1. Of the MMPs studied, MMP-3 levels were found to be significantly reduced after NSAIDs treatment. Therefore, serum MMP-3 levels in OA patients could be proven to be a useful evaluating marker of treatment on the cartilage level. 2. No significant differences were observed among NSAIDs administered with regards to their effect on MMPs and TIMP-1 concentration.

Topical delivery of aceclofenac: challenges and promises of novel drug delivery systems

Osteoarthritis (OA), a common musculoskeletal disorder, is projected to affect about 60 million people of total world population by 2020. The associated pain and disability impair the quality of life and also pose economic burden to the patient. Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed in OA, while diclofenac is the most prescribed one. Oral NSAIDs are not very patient friendly, as they cause various gastrointestinal adverse effects like bleeding, ulceration, and perforation. To enhance the tolerability of diclofenac and decrease the common side effects, aceclofenac (ACE) was developed by its chemical modification. As expected, ACE is more well-tolerated than diclofenac and possesses superior efficacy but is not completely devoid of the NSAID-tagged side effects. A series of chemical modifications of already planned drug is unjustified as it consumes quanta of time, efforts, and money, and this approach will also pose stringent regulatory challenges. Therefore, it is justified to deliver ACE employing tools of drug delivery and nanotechnology to refine its safety profile. The present review highlights the constraints related to the topical delivery of ACE and the various attempts made so far for the safe and effective topical delivery employing the novel materials and methods.

Extracellular matrix degradation and tissue remodeling in periprosthetic loosening and osteolysis: focus on matrix metalloproteinases, their endogenous tissue inhibitors, and the proteasome

The leading complication of total joint replacement is periprosthetic osteolysis, which often results in aseptic loosening of the implant, leading to revision surgery. Extracellular matrix degradation and connective tissue remodeling around implants have been considered as major biological events in the periprosthetic loosening. Critical mediators of wear particle-induced inflammatory osteolysis released by periprosthetic synovial cells (mainly macrophages) are inflammatory cytokines, chemokines, and proteolytic enzymes, mainly matrix metalloproteinases (MMPs). Numerous studies reveal a strong interdependence of MMP expression and activity with the molecular mechanisms that control the composition and turnover of periprosthetic matrices. MMPs can either actively modulate or be modulated by the molecular mechanisms that determine the debris-induced remodeling of the periprosthetic microenvironment. In the present study, the molecular mechanisms that control the composition, turnover, and activity of matrix macromolecules within the periprosthetic microenvironment exposed to wear debris are summarized and presented. Special emphasis is given to MMPs and their endogenous tissue inhibitors (TIMPs), as well as to the proteasome pathway, which appears to be an elegant molecular regulator of specific matrix macromolecules (including specific MMPs and TIMPs). Furthermore, strong rationale for potential clinical applications of the described molecular mechanisms to the treatment of periprosthetic loosening and osteolysis is provided.

COX-2 and iNOS are critical in advanced glycation end product-activated chondrocytes in vitro

BACKGROUND

The advanced glycation end products (AGEs) accumulate in joints of osteoarthritis patients. This study aimed to investigate the roles of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) pathways in AGE-mediated cartilage damage.

MATERIALS AND METHODS

Methylglyoxal-modified albumin was used as the source of AGE. Porcine and human chondrocytes were prepared from the joint cartilage of pigs and osteoarthritis patients. The activation of COX-2, iNOS, nuclear factor-kappaB (NF-kappaB), activator protein-1 (AP-1) and protein kinases was determined by Western blotting, kinase assay, electrophoretic mobility shift assay (EMSA) or transfection assay. Prostaglandin E(2) (PGE(2)) and NO concentrations were determined by enzyme-linked immunosorbent assay (ELISA) and Griess reaction respectively. The enzymatic activity of COX was determined by measuring the conversion of arachidonic acid to PGE(2). The release of sulphated glycosaminoglycan and the intensity of Safranin O staining were used to measure cartilage degradation.

RESULTS

AGE potently induced COX-2-PGE(2) and iNOS-NO activation in porcine and human chondrocytes. Meanwhile, the upstream molecules regulating COX-2/iNOS activation, such as AP-1, NF-kappaB, extracellular signal regulated protein kinase (ERK) and c-jun N-terminal kinase (JNK), were activated by AGE. Although AGE could not activate p38 directly, by measuring COX enzyme activity, the inhibition of p38 resulted in suppressing AGE-induced conversion of arachidonic acid to PGE(2). Furthermore, successful blockage of either COX-2 or NOS activity significantly reduced AGE-mediated proteoglycan release and cartilage degradation.

CONCLUSIONS

This study highlights the significance of COX-2 and iNOS pathways in AGE-mediated OA pathogenesis and their potential as therapeutic targets that are beyond pain killing for OA treatment.

In vitro effects of non-steroidal anti-inflammatory drugs on cytokine, prostanoid and matrix metalloproteinase production by interface membranes from loose hip or knee endoprostheses

OBJECTIVE

To study the effects of the non-steroidal anti-inflammatory drugs (NSAIDs) aceclofenac, piroxicam, tenoxicam and indomethacin on cytokine, matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and prostaglandin E2 (PGE2) production, by interface membranes (IFT), obtained at revision surgery for aseptic loosening of total joint arthroplasty. Involvement of these soluble factors is well documented and probably, a pharmaceutically induced inhibition of them might retard loosening.

METHODS

IFTs from 10 patients with a loose hip or knee endoprosthesis were collected. The possibility of septic loosening was thoroughly excluded by histopathologic and microbiologic evaluation. IFTs were cultured in the absence or presence of the tested drugs and the levels of the soluble mediators were determined, using electrophoretic and enzyme-linked immunosorbent assay techniques. Paracetamol was used as neutral drug.

RESULTS

All NSAIDs exhibited a pronounced inhibitory effect upon the production of interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha). This specific effect on IL-6 is reported in the literature for the first time. The majority of NSAIDs also induced the production of IL-1beta in an adequate portion of samples. These drugs did not have a clear effect on MMP synthesis, but they had a stimulatory tendency on TIMP-1 production. Paracetamol, significantly decreased the synthesis of TNF-alpha and that of the gelatinases.

CONCLUSION

Our in vitro results are encouraging, since it appears that the action of NSAIDs, globally considered, may be beneficial upon the loosening process. The inhibitory effect of paracetamol upon TNF-alpha and gelatinases is intriguing. Our data, if supported by similar observations, probably justify performance of long-term clinical trials.

Efficacy and safety of aceclofenac in the treatment of osteoarthritis: a randomized double-blind comparative clinical trial versus diclofenac - an Indian experience

OBJECTIVE

Osteoarthritis is one of the most common forms of arthritis seen in primary care. Non-steroidal anti-inflammatory drugs (NSAIDs) play an important role in the management of osteoarthritis. However, gastrointestinal (GI) side effects limit their use. Cyclooxygenase-2 (COX-2) selective inhibitors exhibit better GI tolerability than conventional NSAIDs, but their cardiovascular safety is controversial. An NSAID with high efficacy, high GI tolerability and devoid of adverse cardiovascular effects is therefore a profile preferred by physicians. Aceclofenac is an anti-inflammatory and analgesic drug with preferential COX-2 inhibition. The objective of this study was to assess the efficacy and safety of aceclofenac in the treatment of osteoarthritis in an Indian population.

RESEARCH DESIGN AND METHODS

The trial was controlled, comparative, randomized, and double-blind. The study included 247 patients (82 males and 165 females, 40-82 years), suffering from osteoarthritis. Patients were randomized to receive either aceclofenac (100 mg twice daily) or diclofenac (75 mg twice daily).

MAIN OUTCOME MEASURES

Clinical assessment was done at screening, randomization, and at 2 weeks, 4 weeks and 8 weeks of treatment by calculating Western Ontario MacMaster (WOMAC) scores, time taken to walk 100 feet, visual analogue scores for pain, investigator's assessment on a Likert scale and joint tenderness. Tolerability assessment was based on adverse events. Patient compliance was also assessed.

RESULTS

Aceclofenac was found to be statistically superior to diclofenac in efficacy parameters of WOMAC scores, investigator's assessment and joint tenderness. Aceclofenac was found to be statistically superior to diclofenac in terms of epigastric discomfort, dyspepsia and abdominal pain. Compliance was also better with aceclofenac. The overall response of patients' osteoarthritis to aceclofenac was found to be statistically superior to diclofenac by both physician and patient.

CONCLUSIONS

Aceclofenac is an effective and well-tolerated drug in osteoarthritis in the Indian setting.

Pain and osteoarthritis: new drugs and mechanisms

PURPOSE OF REVIEW

This review discusses the recent literature on drugs used for symptomatic pain relief in patients with osteoarthritis (OA) as well as potential mechanisms underlying their pharmacologic action.

RECENT FINDINGS

Recent research has shed light on the molecular mechanisms underlying the contribution of prostaglandins to pain sensation. Moreover, the role of the enzymes cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) in inflammation and subsequent structural changes of joints has been clarified. Based on the COX-1/COX-2 hypothesis, various selective COX-2 inhibitors with improved gastrointestinal tolerability as compared with conventional nonsteroidal anti-inflammatory drugs (NSAIDs) have been established for the symptomatic treatment of OA in recent years. Rational therapy with these compounds should be based on their diverse pharmacokinetic characteristics. Among the traditional NSAIDs, the mode of action of aceclofenac has been recently clarified in that the compound was shown to elicit preferential inhibition of COX-2 as a result of limited but sustained biotransformation to diclofenac. Novel mechanisms have also been proposed to account for the action of acetaminophen. Finally, there is evidence from animal models to suggest that the dual LOX/COX inhibitor licofelone may stop disease progression in OA. Clinical studies are under way to establish this compound for treatment of OA.

SUMMARY

It is anticipated that new insights into the pathophysiology of OA as well as novel therapeutics will improve the pharmacologic options in OA.

Different in vitro activity of flurbiprofen and its enantiomers on human articular cartilage

The 2-arylpropionic acid derivatives or 'profens' are an important group of non-steroidal anti-inflammatory drugs that have been used for the symptomatic treatment of various forms of arthritis. These compounds are chiral and the majority of them are still marketed as racemate although it is known that the (S)- form is the principal effective in the cyclooxygenase inhibition. However, recent findings suggest that certain pharmacological effect of 2-arylpropionic acids cannot be attributed exclusively to the (S)-(+) enantiomer. To obtain further insights into the pharmacological effect of profens, the present study investigated the influence of racemic and pure enantiomers of flurbiprofen on the production of nitric oxide and glycosaminoglycans, key molecules involved in cartilage destruction. The culture of human articular cartilage stimulated by interleukin-1beta (IL-1beta), which plays an important role in the degradation of cartilage, has been established, as a profit experimental model, for reproducing the mechanisms involved in the pathophysiology of arthritic diseases. Our results show that mainly (S)-(+)-flurbiprofen decreases, at therapeutically concentrations, the IL-1beta induced cartilage destruction.

Nonsteroidal anti-inflammatory drugs induce apoptosis in association with activation of peroxisome proliferator-activated receptor gamma in rheumatoid synovial cells

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been reported to induce apoptosis in a variety of cell lines. In this study, we examined the effect of NSAIDs on the growth and apoptosis of synovial cells from patients with rheumatoid arthritis and analyzed the activation of peroxisome proliferator-activated receptor gamma (PPARgamma) as a possible mechanism of action of NSAIDs. Cell proliferation and viability were assessed from 5-bromo-2'-deoxyuridine incorporation and by 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) assay, respectively. The apoptosis of synovial cells was identified by DNA fragmentation assay and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. Indometacin, diclofenac, oxaprozin, and zaltoprofen reduced cell proliferation and induced apoptotic cell death in synovial cells, whereas ketoprofen and acetaminophen did not. N-[2-(cyclohexyloxyl)-4-nitrophenyl]-methanesulfonamide (NS-398), a selective cyclooxygenase-2 inhibitor, also inhibited cell proliferation, whereas it did not cause apoptosis. Rheumatoid synovial cells expressed PPARgamma mRNA, and the PPARgamma ligands 15-deoxy-Delta(12,14)-prostaglandin J(2) and troglitazone reduced the proliferation and induced apoptosis in synovial cells. Luciferase reporter assay demonstrated that not only PPARgamma ligands but also NSAIDs, which could induce apoptosis, increased the activation of PPARgamma in synovial cells. Furthermore, the ability of NSAIDs and PPARgamma ligands to stimulate the activation of PPARgamma correlated with their ability to decrease cell viability(r = 0.92, p < 0.01) and ability to induce DNA fragmentation (r = 0.97, p < 0.001) in synovial cells. These results suggest that PPARgamma is an attractive target for induction of apoptosis in rheumatoid synovial cells and that the activation of the PPARgamma pathway is associated with the apoptotic action of NSAIDs.

Comparison of cathepsins K and S expression within the rheumatoid and osteoarthritic synovium

OBJECTIVE

To determine and compare the expression of cathepsins K and S proteins in joints with rheumatoid arthritis (RA) and osteoarthritis (OA) and to determine the effect of interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF alpha) on the expression of cathepsin K in fibroblast-like synoviocytes.

METHOD

Expression and localization of cathepsins K and S were determined by immunohistochemistry in the synovium of 10 RA- and 8 OA-affected joints. Northern and Western blot analyses were performed to analyze cathepsin K and S expression in primary fibroblast-like synoviocyte cultures from RA and OA patients. The effect of IL-1 beta and TNF alpha on the expression and secretion of cathepsin K in primary cultures of synoviocytes was determined by real-time polymerase chain reaction and Western blot analysis. Staining of in situ activity was used to identify active cathepsin K enzyme in primary synovial fibroblast cultures.

RESULTS

Cathepsin K and S protein expression was identified in the synovium from patients with RA and OA. Cathepsin K protein was localized in synovial fibroblasts, stromal multinucleated giant cells, and, to a lesser degree, in CD68+ macrophage-like synoviocytes. Of note is the expression of cathepsin K in synovial fibroblasts and mononuclear macrophage-like cells at sites of cartilage erosion in RA and in interdigitating cells of lymphocyte-rich areas. In contrast, cathepsin S expression was restricted to CD68+ macrophage-like synoviocytes, interdigitating cells, and endothelial cells of blood vessels. Cathepsin K protein expression in the interstitial areas and perivascular regions of RA-derived synovial specimens was 2-5 times higher than in OA samples (P < 0.001), whereas the expression of cathepsin S did not significantly differ in these diseases. Cathepsin K expression levels in normal synovium were low and restricted to fibroblast-like cells. Of note, cathepsin K also was expressed in repairing fibrocartilage in 1 OA specimen. Primary cell cultures of RA- and OA-derived synovial fibroblasts expressed comparable amounts of cathepsin K at the transcript and protein levels. Both cell cultures secreted mature cathepsin K as well as procathepsin K, and expressed active cathepsin K in cytosolic vesicles. In contrast, neither RA- nor OA-derived fibroblasts expressed detectable levels of cathepsin S. IL-1 beta and TNF alpha stimulated the transcript (7-8-fold) and protein expression (2-fold) of cathepsin K (P < 0.05) in primary synovial fibroblast cultures, without differences in expression between RA- and OA-derived synovial fibroblasts.

CONCLUSION

The presence of cathepsin K polypeptide in synovial fibroblasts and macrophage-like cells in normal, OA, and RA synovia suggests a constitutive expression of this protease and a role in synovial remodeling. The comparable increase in cathepsin K expression after stimulation of RA- and OA-derived synovial fibroblasts with IL-1 beta and TNF alpha further suggests that the expression of cathepsin K is independent of cellular alterations leading to the invasive phenotype of RA-synovial fibroblasts. However, the overexpression of cathepsin K in RA synovia due to an increase in the number of cathepsin K-expressing cells identifies this enzyme as a candidate protease for the pathologic degradation of articular cartilage. Cathepsin S expression in macrophage-like synoviocytes suggests dual activity in antigen presentation and matrix degradation in the inflamed synovia.

Aceclofenac: a reappraisal of its use in the management of pain and rheumatic disease

Aceclofenac is an orally administered phenylacetic acid derivative with effects on a variety of inflammatory mediators. Through its analgesic and anti-inflammatory properties, aceclofenac provides symptomatic relief in a variety of painful conditions. In patients with osteoarthritis of the knee, the drug decreases pain, reduces disease severity and improves the functional capacity of the knee to a similar extent to diclofenac, piroxicam and naproxen. Aceclofenac reduces joint inflammation, pain intensity and the duration of morning stiffness in patients with rheumatoid arthritis, and is similar in efficacy to ketoprofen, diclofenac, indomethacin and tenoxicam in these patients. The duration of morning stiffness and pain intensity are reduced, and spinal mobility improved, by aceclofenac in patients with ankylosing spondylitis, with improvements being similar to those observed with indomethacin, naproxen or tenoxicam. Aceclofenac is also effective in other painful conditions (e.g. dental and gynaecological). In contrast to some other NSAIDs, aceclofenac has shown stimulatory effects on cartilage matrix synthesis. Aceclofenac is well tolerated, with most adverse events being minor and reversible, and affecting mainly the GI system. Although the incidence of GI adverse events with aceclofenac was similar to those of comparator NSAIDs in individual clinical trials, withdrawal rates due to these events were significantly lower with aceclofenac than with ketoprofen and tenoxicam. Superior overall and/or GI tolerability of the drug relative to other NSAIDs has been indicated by a nonrandomised comparison with sustained release diclofenac in 10,142 patients, a meta-analysis of 13 comparisons with diclofenac, naproxen, piroxicam, indomethacin, tenoxicam or ketoprofen in 3574 patients, and preliminary details of a comparison with 10 other NSAIDs in 142,776 patients. Further analysis of the above meta-analytical data has indicated that costs incurred as a result of adverse event management are lower with aceclofenac than with a range of comparator NSAIDs.

CONCLUSIONS

Trials of 2 to 6 months' duration have shown aceclofenac to be an effective agent in the management of pain and rheumatic disease. Data from in vitro studies indicate properties of particular interest with respect to cartilage matrix effects and selectivity for cyclo-oxygenase-2. Aceclofenac is well tolerated, with encouraging reports of improved general and GI tolerability relative to other NSAIDs from a meta-analysis of double-blind trials and from large nonblind studies.